1. Field of the Invention
The disclosure relates to an image formation apparatus and an image formation method, which are advantageously applicable to an image formation apparatus that uses an optical sensor as a detector of the position of a label sheet to control the conveyance of the label sheet and that controls the timing for driving the optical sensor.
2. Description of Related Art
A conventional image formation apparatus uses an optical sensor, such as a transmission sensor or a reflective sensor, to detect the position of a medium being conveyed or to identify a position to start image formation. After the detection, the apparatus conveys the medium by a predetermined amount based on a result of the detection by the optical sensor, and then starts certain processing among various kinds of processing such as printing. Such an optical sensor has variations in the light emission characteristics and light reception characteristics among sensor elements and decreases in light emission due to deterioration with age. For a stable media detection, an apparatus is known for adjusting a slice level in an optical sensor (see, for example, Japanese Patent Application Publication No. Hei 04-085241).